Google, the company with the most frequently used search engine, has been beefing up its other features over the last several years in an effort to develop more user-generated, interactive content. The Mountain View, Calif., company allows users to suggest better words and phrases for Google's computer-automated language translator, for example, and it helped develop standards for creating applications on social networking sites such as MySpace and Google's Orkut. The new map feature is part of this larger effort to exploit the collective knowledge of Google users.

Starting this week, users with Google accounts can move the small green arrows that pinpoint addresses on its maps.

To avoid "monkeying with markers," Google said, there are restrictions on which markers may be edited: Moving a place marker more than 200 yards requires Google's approval. Users also cannot edit the locations of schools, hospitals, police stations or businesses that are registered with Google's Local Business Center. Visitors to Google Maps can choose to see the original location for all markers that have been changed.

Google has been expanding its map features for several months. Last summer, the company began allowing customers to create business reviews on public maps and build customized maps. Users can create a hiking map or post photos alongside geographical locations, for example, and share these maps with friends.

While Google does not make money directly from the additional free services, it hopes they will keep users on the site longer and allow the company to post more ads. Google is the leader in text ads and plans to merge with DoubleClick, the online image and video ad leader, pending Federal Trade Commission approval.